R. 64(1) EPC (former R. 46 EPC 1973) was amended by decision of the Administrative Council (OJ 2009, 299), and entered into force on 01.04.2010.

Under R. 64(1) EPC if the EPO considers that the European patent application does not comply with the requirement of unity of invention, it shall draw up a partial search report on those parts of the application which relate to the invention, or the group of inventions within the meaning of Art. 82 EPC, first mentioned in the claims. It shall inform the applicant that, for the European search report to cover the other inventions, a further search fee must be paid, in respect of each invention involved, within a period of two months. The European search report shall be drawn up for the parts of the application relating to inventions in respect of which search fees have been paid.

In G 2/92 (OJ 1993, 591) the Enlarged Board of Appeal stated that an applicant who fails to pay the further search fees for a non-unitary application when requested to do so by the Search Division cannot pursue that application for the subject-matter in respect of which no search fees have been paid. Such an applicant must file a divisional application in respect of such subject-matter if he wishes to seek protection for it (CA/29/09). It also stated that if the applicant has not availed himself of the opportunity to have the search results on the other inventions included in the search report because he has paid no additional search fees in response to the invitation under R. 46(1) EPC 1973, he will be taken to have elected that the application should proceed on the basis of the invention which has been searched (see G 2/92). However, non-payment is not to be equated with the abandonment of parts of the application.